One Way Ticket to Mars?

I love the idea of visiting space, and when I win more than
£6.70 on Euromillions I fully intend to buy myself a ticket on one of those Virgin
Galactic flights.

But the Mars trip has one major drawback. The article says
that the four volunteers will be given a ‘one-way ticket’ to the Red Planet.
Then it shows them smiling, doing domestic chores and looking all well-adjusted
and normal. One woman casually says: ‘The majority of my communication with my
family is by phone or text anyway, so I'm used to having them at a distance.’
What? How mad do you have to be to say goodbye to everyone you know and head
off into space for the rest of your life? How are these people passing any kind
of psychological test? Surely anyone that emotionally detached is likely to
chop everyone else in the colony into tiny pieces then listen to Beethoven and
drink tea as though nothing has happened?